1. Field of the Invention
The present invention relates to wicks. More particularly, the present invention relates to wicks resistant to fraying. While the invention is subject to a wide range of applications, it is especially suited for use in liquid fuel appliances; and will be particularly described in that connection.
2. Description of the Related Art
Wicks are absorbent material adapted for liquid transfer applications. Although often used to transfer liquid fuel to a point of combustion, wicks may also be used for transfer of ink and lubrication, air freshener and perfume delivery, and gas and liquid filtering applications.
Traditionally, wicks have been manufactured as long strands of absorbent material. During manufacturing, these strands are cut into usable lengths. Not only may the process of cutting the wick strand fray the wick as cut, but it also exposes the wick to additional fraying during use.
To reduce this fraying, mechanical means for binding the ends of the wick have been used. For example, metal wire has been wrapped around the end portion of the wick to prevent fraying or the ends have been bound by tying a knot in the wick to prevent fraying beyond a predetermined point.
The mechanical means for reducing fraying of wicks have many disadvantages. The mechanical means involve an added step in the wick manufacturing process, which adds to the costs of the product. Furthermore, during use, a wick is often inserted into an opening that is of the same inner diameter as the outer diameter of the wick. Mechanically fastening a wick end to prevent fraying can add to the overall dimension of the wick or distort the shape of the wick. Either way, such change in shape can make it more difficult to insert the wick into the device in which it is used. This difficulty can increase the cost of manufacture for the device in which the wick is used, and may increase the cost of maintenance for such a device, by increasing the labor necessary to position the wick.
Mechanical means for reducing fraying have another disadvantage. Mechanical means, such as wire or knots can restrict or prohibit fluid flow along the wick beyond a certain point on the wick.
Non-mechanical means for reducing fraying are also disclosed in the prior art. For example, an absorbent inner core wick may be surrounded by a nonabsorbent nonporous plastic wrap. The plastic wrap is intended to reduce the fraying of the absorbent inner core. This wick construction, however, has certain disadvantages. In particular, because of the outer plastic wrap, such a wick is not absorbent along the outer periphery of its length. Absorption is limited only to the cross-sectional area of the end of the wick. This, of course, reduces the effectiveness of the wick itself.
In another non-mechanical means, the outer portion of a wick core material is heat-fused to an open mesh braid of textile strand material surrounding the core. The braid binds the wick and helps to reduce fraying while the open portions of the mesh element allows for some absorption along the outer wall of the wick. Accordingly, there is some improvement in absorption by the wick as compared to the prior art of a complete plastic wrap. There is, however, still restriction along the mesh portion of the outer walls of the wick.
In light of the foregoing, there is a need for a wick, and method of making such a wick, that will reduce the fraying of the wick by nonmechanical means while maximizing absorption of the wick.